Fusible link



p 1932. w. L. ROESSNER 1,875,661 FUSIBLE LINK v Filed Sept. 8. 1931 &voentow Patented Sept. 6, 1932 UNIT1SD ST'ATES WILLIAM IQ. ROESSNEIR, 01 DENVER, COLORADO Applicatidn flle d September This invention relates to improvements in fusible links of the type -ern p loyed in comnection With fiie extinguishing apparatus anc1 fire doors.

In large office buildings and factories, it is customary to provide stair'wells andelevator shafts extending from thetop of the building to the bottom an ;l at each floorthere 2'11e doo'r openingsthrough which entrance may be had to the stairway and into the elevator; and these openings are provided with heavy fire doors that are biased t closed position by means of weights 01 springs and are held in open position by meansof a. fusible link that is so constructed that it will fail When"the temperature reache's g predetermined value.

It quite frequently happens that With the ordinary type of fusible link, fire do0rs and other appar2mts that is held in openposition by fusible linkswill be releas 'ed a times 'When theate isn0 occasion for the'm to nve and this aside from the inqonvenience that it causes, is fr6qently tl1e, canse of serious 2pccident. 1 y

I1: is one of the objects 0f this inventionto produc6 a fusible link of such Construction that it can be relied upon at ll tiniesto perform its function' and Whicl 1 will resist very large forces m compar1son W1th 1ts s1ze.

. Links of the type to Which this inventi0n relates,"eind which will be described herein, can be used in many different places, but the specific link shoWn and dscribed Will.beillustrated asapplie'd t0 a fire door; but itis t0 be unclerstood that its use is not t bg limited in any'way'by this illustration.

This invention briefly describecl, consists of a fusible link struc'ture comprisihg a plte having an opening and a cooperating part forme d of two'parallel arms that extend through the opening in the plate and are then spread apartand held in spreacl position b V means cf a plug ofeasily fusible sold'er.

When a frce is applid which tends to remove the arms from fohe plante, this force Will be resisted by the outwarclly inclined ends Which are held against inward moVement by the plug. Since the plug is Sub jected only 130 compressive strains, it Will s, 1931. Sgrll N0. 561,667.

positively re'sisi: very larg6forCes Withont danger of faih1're as diStinguished from links th at am held togethe r by easily fusible solder and in which the stralins atre reSisted' by the tensil strength of the solder. v In order to describe this i1'1Ventionso that it can be mo'st readily uriderstood, refe1encia will behad t0 the ccompanying drwing in which it has been illustrzttedin its pref e1re'd f01m',and in Which': Fig. 1 is a section through a fire Wall sh0W- ing a fire doof held in opnflpos'ition by the fusible link that frrns the subjecip of this invention;' V Fig. 2 isa"side link; Fig. 3 is a section taken on line 3"3, Fig. 2; Fig. 4 is a Viewshowing the' parallel -arms tl1at forrhs ne'part of fihe link; anti .Fig. 5shows ai Slightly difl'erent embodiment of the invention.; In the Qmbodimenbof the invkantion shbvi7fi in Fi'gs; 2 aind- 3, a casing comprisihg a tube 1 hasbeen shown. One end of this tube iS closed by a tranSfirersememb6r2 that has an opening. 3f01 the recepti0n Cf the haui1pin like st'rncture 'showni'n Figl4. Thfs strucv tur.e consis ts of' a.flxible piece"of steel ribbon that .is bent double. The ends 4 2t re eleyation of the improv a curved .ontwardly for a shorn distaiice ar1d ahe extre1'netips arebe'nt inwlardly a's indi- 'cated by reference num'eral 5. Located within'the taube 1 is a spring 6 and secured to.the Open end ofthe tube isa b'ail 7. This bail may b6 held inlplace by means ofrivet5 8 01 it may be welded or otherwi3e s ecured to th ev tube. -1;1Xvvasher 9 is provided With a rectangular opening sind thisflis thteaded onto the' inner 'end 0f the structuria shovlm in Fig. 4; After the ends 4 ha ve ben passed through the wamsher9, a plug 10 f easily fusiblg solder is put into place betwen the end Portions 4 and holds them spread apart t0 such an extent that they will longer pass thx0ugh the opening in the washer. The assefi1bly shown in Figs. 2 ancl 3 can be subjected a conSiderable for'ce tending to Separate theflexible' zirms from the remaindepthereof withou tdanger of the parts failing because' the force is"resisl:ed by the 100 wvhich exerts a force tending to close plug 10, which, although it is easily fusible, is eomposed of solid material that Will not reaclily crush. In Fig. 1 an assembly like that just described has been anchorecl at one end. to the Wall 11 and ab the other encl t the fire cl00r 12. This door is biasecl to closecl position loy means of a calole 13 ancl a weig lit 14. Oi, if the cable and Weight are not desired, they can be replaced by a spr1rfig t e door. If a fire breaks out in theibnilding, or if the temperature rises for any reason until it exceeds the temperature neceSsary to fuse the plug 10, 13116 parts can then be easily sparated becase the arms of which portions 4 for1n a part, are made very flexible ancl unless they are held separated by son1e solid inaterial, they Will offer Very small resistaince against compression. Where the parts are constructecl as shownin Figs.

' 2 and 3, the spring 6 Will funCtion t0 push the factory.

alle Washer 9 over the encls 4 as soon as the plug has meltecl and this assists to sonne extent in ehe operation of the device. Another function for spring 6 is that wl1en this spring iss useol, the fusible plug will be helcl in place with greater security thanifthe spring were not in use, ancl therefore the fusible links can be shippeol in fully assembled condition which assures thai; they Will be correctly assembled, as the assemblying can be done at have shown a slightly diflerent form of the invention. The Inain difl'erence between that shown in Fig. anrl What is shown in Figs. 2 and 3, is that in Fig. 5, the tube 1 has been ornitted and the bail 7 has its ens attached to a perforated transverse portion that corresponds to the washer Fig. 3. A washer 16 taks the place of botto1n 2 in Fig. 3'. The fusible plug is pro vided Wlth grooves on oppoSite sicles and t hese grooves are of '13l16 proper d epth and width to receive {die ends 4. The fusible In Fig. 5 1

' plug is securely helcl in place due to the grooves anal to the action of the spring.

From the above description itwill be apparent that the simple construction shown and described results in a Very dependable fusible link that Will resist high strains witl1- 01111 danger 0f prematurely failing and it is therefdre especially Well adapted, for use with fire protective apparatus of all kinds such as the fire cloors which reference has been 1nacle and automatio sprinkler systerns aswell as 'other types of fire extin'guishing apparatus.

Havi g clescribed the -inventi0n what is claimedas new is:

l. A fusible link f0r use in controlling temperature responsive apparatus, comprising in combination, a mernber having an opening a seconcl rne1nber ha ving two substantially parallel arms adaptecl 130 pass through the opening, the encls of the armsbeing inclinecl outwardly so as to be spaced farther apart than the width 0f the opening, and a plng of readily fusible 1naterial interposecl between the ends of the arms 130 hold the1n in spreaol relation and thereby prevent their withdrawal through the opening.

2. A f usilole link for use in Controlling temperature responsive; apparatus, c0mpris ing, in oombination, a 1ne1nber having an o 'pening, a second member having two substantially parallel arnis adaptecl to pasS through the opening, the ends of the arms bein inclinecl outwarclly so as to be spaced fartl1er apart than the width 0f the opening, a plug0f readily fusibl6 material interposed betweenthe encl s of the arms to hold them in spreacl ielation ancl thereby prevexit their witholrawal thr0ugh the openingand means foriorcing the member having the opening against the inclinecl outer surfaces of the ar1ns Whereby the latt er Will be forced'agxinst the oiltside 0f the plug.

3. A fusible link of tlne type' describecl, coinprising.in combination, two relatiVely movable arid separable' members, one f which comprises a me1nber providecl with an opening ancl the otl1er of Which comprises two substanpially parallel flexiblearms, one end 0f the arn1s beingattachecl to.each other ancl t-he other encl extending through the Opening in the other mernber, the ends that extend through the opening being spread apart so that the distance between their outer surfaces is greater than the corresponding Width of the opening, and a plug of fusible material interposed between the spread ends. y 1

4 A fusible link of tlie type desc1iibed, 00mprising, in combinatinwo relatively movable and separable members, one of Whioh comprisesa member provided with an Opening and the other 0f which comprises two substantially parallel flexible arms, one enl of tl1e arrn s being attached to each other and the other engl extending through the opening in the -other member, the ends that extend through the opening being spread apart so that the" distance between their outer surfaces is grefcer than tl1e correspondirig. wid th of the.operiing a plug o f fusible material interposed between the spreaol ends and resilient 1neans associated with the parts f0r prodlicing a force tendihg so withdraw the ar1ns fro1n the opening.

-5. A fusible link of the type d6scribied, comprising, in combination, a tubular memloer having one end providecl with a bottom and the other encl open, tlie bottom having an opening, a helical spring in the tubular membe1, the length of the spring being greater than that of the tubular me1nber whereby when one encl of the spring rests onfhe bottom, the other end Will extend t0 the outside of tl1e tubular n1ember, a meimber comprising two substantially parallel resilient armsf extencling through the tubular member and through the spring, the ends of the arms being bent so as to be outwardly inclined, a plate having an opening, said plate being 10- cated at the outer end of the spring, the ends of the arms extending through the opening, and a plug of fusible material located between the outer ends of the arms.

6. A fusible link 0f the type described, comprising, in combination, a, tubular member having one end provided with a bottom and the other end open, the bottom having an opening, a helical spring in the tubular memher, the length of the spring being greater than that of the tubular member whereby when one end of the spring rests on the b0t tom, the other end will extend t0 the outside of the tubular member, a member eomprising two substantially parallel resilient arms extending through the tubular member and through the spring, the ends of the arms being bent so as t0 be outwardly inclined, a plate having an opening, said plate being 10- cated at tl1e outer end 0f the spring, the ends of the arms extending through the opening, a plug of fusible material located between the outer ends 01 the arms, and means for anchoring the plug in place.

In test1mony whereof I aflix my sigriature.

WILLIAM L. ROESSNER. 

